ECOLOGY: PORT JACKSON SHARKS 



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were made within a month after tagging. Almost twice as many resightings 

 were made after an interval of 4 months than were made over the period of 

 1 to 4 months. In other words, most sharks were resighted either within a 

 week of tagging or 4 months afterwards. In more recent studies (Nash and 

 O'Gower, unpublished data) several sharks transferred from particular reefs 

 and bays in the Harbour (Rose Bay and Middle Head) have been recovered 

 at their original resting site at the Sow and Pigs, while some natural traffic 

 has been noted between various reefs in the Harbour (e.g., from South Head 

 to Middle Head and Sow and Pigs, and from Sow and Pigs to Middle Head). 

 McLaughlin and O'Gower (1971) also recorded one horn shark that moved 

 from Middle Head to the South Bondi reef, while a shark tagged at Jervis 

 Bay was found in nearby Disaster Bay and later relocated at the tagging site 

 in Jervis Bay (Table 1). 



These changes in numbers and patterns of shark movements on inshore 

 reefs indicate that most of the sharks were continually moving from and 



Table 1. Tagging and recapture data for H. portusjacksoni 



